The cameras on some new phones don’t show the world as you’ve known it.

Instead of just viewing the usual landscape of people, places and things on their screens, you see circles, rectangles and icons floating on top of the scenery. Tap one to display a snippet of Internet data about whatever lies behind that tag. As you look around, the view on the phone’s display shifts accordingly, presenting new shortcuts to whatever the Web knows about your surroundings.

The concept goes by the name augmented reality, and it’s been quietly bringing one of the Internet’s hokiest promises to a mainstream audience.

Remember all the hype about virtual reality, in which we’d don headsets to immerse ourselves in some version of the Star Trek holodeck? Augmented reality turns this from a science-fiction idea into something you can experience just by holding a smartphone in front of you at eye level — no goofy goggles or helmets needed.

For that to happen, though, mobile phones had to acquire a few prerequisite capabilities: a fast Internet connection, a high-resolution screen, Global Positioning System reception and a compass. In other words, first the phone had to be able to look up things on the Internet, then it had to be able to show them to you, then it had to find itself on a map, then it had to orient itself in 3-D space.

As a result, “AR” programs didn’t begin to appear on consumer hardware until last year, and many otherwise brainy smartphones still cannot run them — for example, the original iPhone and iPhone 3G and Palm’s Pre and Pixi devices lack compasses.